The invention relates to an apparatus for feeding and folding sheet-like objects or a set of sheet-like objects, such as sheets of paper, envelopes, etc.
In small desktop systems for processing mail items compact size is an issue. To reduce size, in many apparatuses various functions, which in large apparatuses are implemented with different structures as rollers or conveyors, are combined in single structure. For instance, the functions of feeding a sheet from a stack and folding the sheet may be combined in one pair of feeding-folding rollers. In such systems, a sheet is positioned near the nip and buckled, e.g. by a wedge, and subsequently the buckled portion is plead and entrained by the folding rollers. By passing the plead portion through the nip, a fold is made in the sheet. In this way the functions of separating a sheet from a stack and folding the sheet are combined. Such apparatuses are known from European patent application 0 312 177, European patent application 0 421 547, U.S. Pat. No. 2,000,636, U.S. Pat. No. 2,493,410 and U.S. Pat. No. 3,057,621.
It is also known to feed and fold a set of stacked sheets using a pair of folding rollers using the wedge to plea and push all the stacked sheets into the nip, so that all the sheets in the stack are folded together. Apparatuses operating in this manner are known from U.S. patent application 2008/0001338 and U.S. Pat. No. 7,121,993.
For folding thick gate folded-paper, such as greeting cards, from European Patent application 1 277 687 a device is known applying a knife that entrains a pair of deflectors having a curved working face for engaging front side portions of the gate folded-paper to be processed. As the stroke of the knife towards a pair of folding rollers is larger than the stroke of the deflectors, which are immobilized at the end of the stroke by notches, the gated folded-paper is pushed trough the nip formed by the pair of folding rollers and subsequently folded.
As described above, the principle of combining feeding and folding rollers is known, however, it is not suitable for folding a set of stacked sheets, as in the case of daily mail (manually gathered sets of stacked sheets). The apparatuses suitable for folding several stacked sheets together can only fold a single sheet individually, when the sheets are fed separately, thus requiring additional means for separating the sheets in a stack prior to folding, such as rollers or conveyors, making the device more complex.